This invention relates to disc drives, and in particular to the assembly of a head gimbal assembly to a disc drive.
A disc drive is more likely to be exposed to large mechanical shock loads when it is not in operation. For example, in portable applications, disc drives may sometimes be dropped. In such situations, the impact of the read/write heads against the discs may cause irreparable damage. One way of preventing such damage is to park the read/write heads off the discs when the disc drive is not in use, as opposed to parking the read/write heads directly on the surfaces of the discs. When the disc drive is in operation, the read/write heads may be found in flight above the disc surfaces.
Each read/write head is often mounted to a slider which is attached to one end of a suspension by gimbals. A flex circuit is usually routed from the read/write heads and along a surface of the suspension. This assembly is referred to as the head gimbal assembly (HGA).
The other end of the suspension is operably connected to an actuator for moving the HGA. When the disc drive stops operating, the actuator moves the read/write heads away from above the disc surface until the HGA comes to rest on a ramp in a process referred to as xe2x80x9cunloadingxe2x80x9d. At the start of disc drive operations, in a process referred to as xe2x80x9cloadingxe2x80x9d, the actuator moves the HGA away from the ramp towards the discs, thereby bringing the read/write heads into flight above the respective spinning disc. One example of a disc drive incorporating a ramp design is described in the U.S. Pat. No. 4,933,785 issued Jun. 12, 1990, to Morehouse, et al. U.S. Pat. No. 6,032,352 issued Mar. 7, 2000 to Furay, et al., describes an actuator supporting a suspension which has a lift tab attached to one side of the suspension. One end of the load lift tab extends beyond the read/write head to rest on the ramp when it is in the xe2x80x9cunloadedxe2x80x9d position.
In the manufacture of disc drives with a ramp design, the HGA has to be put into an xe2x80x9cunloadedxe2x80x9d position, with the HGA resting on the ramp. The assembly is complicated by the fact that a typical disc drive includes more than one disc and that there will be at least one read/write head for reading from or writing to each disc surface. A typical disc drive therefore has an array of read/write heads, arranged in opposing pairs. To minimize the overall size of the disc drive, the spacing between neighboring discs is kept as small as possible. In addition, to facilitate low fly-height, the suspension is pre-loaded to bias the read/write heads towards the disc surface. The opposing pairs of read/write heads must therefore be forcibly held apart from one another when not in flight. For this purpose, a shipping comb formed of an array of pins or teeth may be inserted at the suspensions to keep the read/write heads spaced apart before the HGA is delivered to the ramp. Because the flex circuit can be routed along the surface of the suspension adjacent to the head, the conventional shipping comb tends to rub against the flex circuit, which may possibly damage the flex circuit.
There remains therefore a need for an improved method and apparatus for delivering the HGA to the ramp in the manufacture of disc drives. As described in the following, the present invention provides this and other advantages over the prior art.
The present invention provides for an improved method of assembling a disc drive. According to one embodiment of the present invention, the method involves the use of a shipping comb which is configured for engagement with the load beam of a head gimbal assembly. The method involves the use of a ramp which is arranged and configured for engagement with the load beam.
In one preferred embodiment, the load beam is transferred from the shipping comb to the ramp when the teeth of the shipping comb is brought into abutment with the ramp. In a most preferred embodiment, the shipping comb and the ramp are brought into self-alignment by first features on the shipping comb and complementary second features on the ramp.
In another aspect, the present invention provides for a shipping comb which is configured to receive an array of load beams. Each load beam extends beyond a head gimbal assembly away from the suspension. Preferably, the shipping comb is configured for self-alignment with a ramp. In one embodiment, the shipping comb includes first features complementary to second features of the ramp. Preferably, the first features are at a proximal end of at least one shipping comb tooth, and the second features are at a distal end of at least one corresponding ramp tooth.